So the 4.0.1 update is available for your iPhone, and according to most people is does nothing to fix the iPhone4 issues but does show AT&T's network in an even less appealing light (if that's even possible.) However, what if you want to roll back for some reason? The newer versions of iTunes allow only one backup of each phone. But there's a workaround that's pretty easy to do. I did this in case this update turns out to be extra unhelpful.